Ah, I had looked at the "previous post", but there was no image. I guess he edited the post to remove the image so. Guess I'd better not take up a hacking career - I'd not get very far.   Even took me a couple of minutes to figure out 1337est.  
But wait, OpenYourEyes said he was using a flash beacon to catch the IPs. I found this which shows how to embed flash code into a forum post, and the first reply says "allowing users to embed flash is a security risk". So... what gives?  OpenYourEyes can't have just used a regular image because that would have gone over joe23's TOR connection - he specifically tried flash which often ignores proxy settings.